# QuestionNASSP Checklist question and operation of Sextant

#### jgrillo2002

##### Conservative Pioneer
Hey everyone. I wasnt sure if this was answered or not but I have some questions regarding specific procedures.
In the CSM/LV Separation checklist, the checklist asks to input to the DSKY
Code:
R1=R1(N20) - 60
R2=R2(N20) + 180
R3=360-R3 (N20)

I have no idea on what to input on the DSKY for that.

Next one. This is on P40 SPS Thrusting during the 1st MCC, the checklist asks me to input in the DSKY
Code:
Enter SXT Star Angles (from Maneuver PAD)
Sextant star visible in Sextant.
I know how that system works but I wasnt sure on how do I get the star angles from the PAD. I dont even know what the pad does nor its function.

Any ideas on how those work?
Thanks

#### indy91

Hey everyone. I wasnt sure if this was answered or not but I have some questions regarding specific procedures.
In the CSM/LV Separation checklist, the checklist asks to input to the DSKY
Code:
R1=R1(N20) - 60
R2=R2(N20) + 180
R3=360-R3 (N20)

I have no idea on what to input on the DSKY for that.

This procedure calculates the docking attitude from the CSM/LV separation attitude. Noun 20 displays the current attitude, so that's the N20. You have to look at V16 N20, write down the numbers and do the math above. Register 1 of Noun 20 minus 60° is the input for Register 1 of Noun 22. And so on. This is essentially a backup method to get the docking attitude angles, normally these numbers can also be found on the TLI PAD (except Apollo 8).

Next one. This is on P40 SPS Thrusting during the 1st MCC, the checklist asks me to input in the DSKY
Code:
Enter SXT Star Angles (from Maneuver PAD)
Sextant star visible in Sextant.
I know how that system works but I wasnt sure on how do I get the star angles from the PAD. I dont even know what the pad does nor its function.

Any ideas on how those work?
Thanks

PAD stands for Pre-Advisory Data. These are forms that contain useful numbers given to the astronauts for e.g. SPS burns or TLI etc. Which NASSP version, which scenario and which mission were you using in this case? Using any of the MCC launch scenarios enables an automatic mission control feature, which will display these PADs automatically. When using the non-MCC scenarios they can be calculated manually with the RTCC MFD, which comes with NASSP.

The numbers on the PADs are usually explained in the flight plans. The sextant star angles are on the Maneuver PAD. See the form and the explanation of each number in this document, PDF pages 54-56.

#### jgrillo2002

##### Conservative Pioneer
OK the scenario of the Sextant issue is the Apollo 8 MCC1. Is it asking for Shaft setting on R1 and Trunnion on R2?